Organic Chemistry Terms Starting with H
Definitions of 43 organic chemistry terms that start with H, such as Haloalkane, Haloform Reaction, Halogen Abstraction. Plain-language explanations linked…
Terms starting with H
- Haloalkane: Alkane containing F, Cl, Br, or I.
- Haloform Reaction: Reaction of certain methyl carbonyl compounds producing a haloform such as CHI₃.
- Halogen Abstraction: Removal/transfer of a halogen atom, often in radical chemistry.
- Halogenation: Adding or substituting halogen atoms into a molecule.
- Halohydrin Formation: Adds OH and X across an alkene.
- Hammond Postulate: A transition state resembles the stable species closest to it in energy.
- Haworth Projection: Common drawing style for cyclic sugars.
- Heat of Combustion: Heat released when a substance burns completely.
- Heat of Reaction: Enthalpy change associated with a reaction.
- Hell–Volhard–Zelinsky Reaction: Halogenates the α-carbon of a carboxylic acid.
- Hemiacetal: Carbon containing both –OH and –OR.
- Henderson–Hasselbalch Equation: Connects pH, pKa, acid, and conjugate base concentrations.
- Heterocycle: Ring containing at least one non-carbon atom such as N, O, or S.
- Heterogeneous Catalyst: Catalyst in a different phase from the reactants.
- Heterolytic Bond Cleavage: Bond breaks and both electrons go to one atom.
- High-Resolution Mass Spectrometry: Very accurate mass measurement useful for determining molecular formulas.
- Hofmann Elimination: Elimination that often favors the less substituted alkene.
- Hofmann Product: Less substituted alkene product of an elimination.
- HOMO: Highest Occupied Molecular Orbital, highest-energy MO containing electrons.
- Homogeneous Catalyst: Catalyst in the same phase as the reactants.
- Homolytic Bond Cleavage: Bond breaks evenly: one electron goes to each atom, creating radicals.
- Homopolymer: Polymer made from only one type of monomer.
- Homotopic: Positions in a molecule that are chemically equivalent by symmetry.
- Hund’s Rule: Electrons fill equal-energy orbitals singly before pairing.
- Hydrate: Compound containing associated water, or a product formed by addition of water depending on context.
- Hydration: Addition of water/H and OH to a molecule.
- Hydrazone: Compound containing C=N–NH₂/NR₂-type functionality formed from a carbonyl and hydrazine derivative.
- Hydride Shift: H moves with its bonding electron pair to a neighboring carbocation center.
- Hydroboration–Oxidation: Converts an alkene into an alcohol with anti-Markovnikov regiochemistry and overall syn addition of H/OH.
- HCFCs: Hydrogen-containing chlorofluorocarbon refrigerants.
- Hydrocracking: Industrial process breaking large hydrocarbons into smaller ones using H₂ and catalysts.
- HFCs: Hydrogen/fluorine-containing compounds used as refrigerants.
- Hydrogen Abstraction: A radical removes a hydrogen atom from another molecule.
- Hydrogen Bonding: Strong intermolecular attraction involving H attached to electronegative atoms such as O or N.
- HDI: Hydrogen Deficiency Index: another name for degree of unsaturation.
- Hydrohalogenation: Adds HX across a double or triple bond.
- Hydrolysis: Uses water to break a bond.
- Hydroperoxide: Compound containing –OOH.
- Hydrophilic: “Water-loving”; interacts well with water.
- Hydrophobic: “Water-fearing”; does not interact favorably with water.
- Hydroxyl Group: –OH group.
- Hyperconjugation: Stabilization caused by interaction of nearby σ bonds with an adjacent orbital/π system.
- Hückel’s Rule: Aromatic systems have 4n + 2 π electrons.
Open a term starting with H
- Haloalkane
- Haloform Reaction
- Halogen Abstraction
- Halogenation
- Halohydrin Formation
- Hammond Postulate
- Haworth Projection
- Heat of Combustion
- Heat of Reaction
- Hell–Volhard–Zelinsky Reaction
- Hemiacetal
- Henderson–Hasselbalch Equation
- Heterocycle
- Heterogeneous Catalyst
- Heterolytic Bond Cleavage
- High-Resolution Mass Spectrometry
- Hofmann Elimination
- Hofmann Product
- HOMO
- Homogeneous Catalyst
- Homolytic Bond Cleavage
- Homopolymer
- Homotopic
- Hund’s Rule
- Hydrate
- Hydration
- Hydrazone
- Hydride Shift
- Hydroboration–Oxidation
- HCFCs
- Hydrocracking
- HFCs
- Hydrogen Abstraction
- Hydrogen Bonding
- HDI
- Hydrohalogenation
- Hydrolysis
- Hydroperoxide
- Hydrophilic
- Hydrophobic
- Hydroxyl Group
- Hyperconjugation
- Hückel’s Rule